Re: [PATCH v2 0/1] MR7439: winedmo: Find mp3 stream info if channel data is missing.

[Rémi Bernon (＠rbernon)]

Rémi Bernon (@rbernon) commented about dlls/winedmo/unix_demuxer.c:
>              continue;
>          }
>      }
> -
>    else if (par->codec_id == AV_CODEC_ID_MP3)
> -
>    {
> -
>        int channels;
>
> +#if LIBAVUTIL_VERSION_MAJOR >= 58
> -
>        channels = demuxer->ctx->streams[i]->codecpar->ch_layout.nb_channels;
>
> +#else
> -
>        channels = demuxer->ctx->streams[i]->codecpar->channels;
>
> +#endif
> -
>        if (!channels)
> -
>            avformat_find_stream_info(demuxer->ctx, NULL);
> -
>    }

```suggestion:-10+0
        else if (par->codec_id == AV_CODEC_ID_MP3)
        {
            int channels;
#if LIBAVUTIL_VERSION_MAJOR >= 58
            channels = par->ch_layout.nb_channels;
#else
            channels = par->channels;
#endif
            if (!channels) avformat_find_stream_info( demuxer->ctx, NULL );
        }
```

But I wonder if this is this the best way to do this. Maybe we should call `avformat_find_stream_info` unconditionally for some formats. It was avoided because it can take a bit more time and we want demuxer initialization to be fastest as possible (to match native and address some Unreal Engine potential race condition), but that's maybe only specific to MP4 as far as I know.